How to ID and Avoid Fungus This Spring

Chrissy Balk, technical advisor with the Davey Institute, talks about fungal issues trees can experience in the spring, such as wood decay fungus and leaf diseases. Learn how to spot them as well as when they pose a threat to the tree versus when they are helpful to the tree.

In this episode we cover:  

• How do you know if a mushroom is good or bad? (0:51)
• Locations where fungus can grow (2:05)
• What happens if you see fungus on your tree? (4:25)
• Fungus growing on a wound (5:57)
• When should you call an arborist? (7:25)
• How to prevent wood decay fungus on trees (10:20)
• Mulching the wrong way (11:41)
• Leaf diseases (12:47)
• What does Chrissy do as a technical advisor with the Davey Institute? (16:32)
• How did Chrissy get involved in this career? (17:18)

To find your local Davey office, check out our find a local office page to search by zip code.

To learn more about what to do about fungus growing near your tree, read our blog, What to do about Mushrooms Growing at the Base of Trees.

Connect with Davey Tree on social media:
Twitter: @DaveyTree
Facebook: @DaveyTree
Instagram: @daveytree
YouTube: The Davey Tree Expert Company
LinkedIn: The Davey Tree Expert Company 

Connect with Doug Oster at www.dougoster.com. 

Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!

Transcript

Doug Oster: Welcome to the Davey Tree Expert Company's podcast, Talking Trees. I'm your host, Doug Oster. Each week, our expert arborists share advice on seasonal tree care, how to make your trees thrive, arborists' favorite trees, and much, much more. Tune in every Thursday to learn more because here at the Talking Trees podcast, we know trees are the answer. I'm joined again this week by Chrissy Balk. She's a technical advisor for the Davey Institute. Today, we're talking about what do you do if you see fungus in your trees? Chrissy, welcome back to the show. Good to see you.

Chrissy Balk: Thanks. Well, thank you for having me again. It's nice to talk to you. It's been a while.

Doug: I know there's just so many different avenues we could go when we're talking about fungal issues with trees. I guess the first thing is that when a homeowner just sees something sprouting somewhere, how do we know if it's a bad thing, a good thing? Is there a way for us to tell, or do we need our arborist to come?

Chrissy: Yes. A lot of times, people say, "Oh, I found a mushroom on my lawn, and it's next to my tree, and my tree looks sad." It must be the mushroom because we grew up thinking mushrooms are bad. From when we were really little, I know my parents were like, "Don't touch mushrooms. They're bad, inherently bad." Which is not true at all. They just have their place everywhere. With a decay fungus in the urban environment, we see them as bad because they can decay our trees and take them down and cause hazards.

In the forest, they're great. The trees are dying that they're infecting, and they're decaying that, and we need that. They're not always bad. It's just how you look at the interaction. Decay in trees isn't always bad. If it's an urban tree, it's bad because it can create hazards. Mushrooms are not always bad.

Doug: We can see mushrooms popping up in the root zone, but we can also see some type of fungal growth at the bottom of a tree. Oftentimes, when I see that, that worries me. I'm calling my arborist right away, and I'm like-- Sometimes it's like, okay, yes, that's an issue. Other times, it's an edible mushroom that has a symbiotic relationship with the tree.

Chrissy: Yes. We can find mushrooms connected to the canopy of a tree, like you said, in the roots of a tree. I'm assuming you were talking about on the trunk of a tree. We can find mushrooms and conch all over the tree. If they are connected to that woody tissue of the tree, that does mean that there's some sort of interaction with decay going on. It is going to be in that spot you find it. The other thing is, just because you find it in one spot doesn't mean it's not in other spots. Keep that in mind, too. If it is there, if you are seeing it on the roots, it doesn't mean it can't be further up on the trunk, meaning there could be decay that whole way.

It also doesn't mean that it is going throughout the tree. If you are finding a mushroom or conch on woody tissue, it does mean there's some sort of interaction with decay going on. Those are always going to be something that are worrisome. If you find mushrooms in your yard and they're not connected to the roots, they're likely mycorrhizal mushrooms and going to be beneficial for the tree. That's my determinant when you're looking for mushrooms that are bad or good in your yard. Are they connected to that woody tissue?

Doug: You talked about mushroom, but what was the other thing that you mentioned there?

Chrissy: Oh, conch. Yes. Actually, those are different categories of fungal fruiting bodies. Fungal fruiting bodies are the overarching term for the reproductive structure of a fungus. Actually, mushrooms are just a category of that. Conchs are just a category of that. They're the fruiting body.

Doug: In general, if I see some kind of fungal thing like a conch or mushroom very close to my tree, we're talking about some kind of decay, but what do I do then?

Chrissy: Once you find that, if you have determined it's connected to the tree and the woody tissues, unfortunately, there's basically nothing you can do, no matter what the species. Because a lot of these wood decay fungi are coming in once the trees are already stressed. Our urban trees, think about them. We put them into these environments. They're going to be stressed even if you do your best. These wood decay fungi come in once these trees are stressed. There's really nothing you can do but prevention. If you can prevent them from being stressed, then there's way less likelihood that they're going to get those infections.

Unfortunately, once you have a wood decay fungus, there's nothing you can do to get rid of that fungus. There are some that you can do things to make it take longer for the tree to succumb to that decay. You can prolong the life by making the trees healthier again, but there's nothing you can do to get rid of it. There's no magic wand that you can use to treat those things. It's unfortunate.

Doug: Do you see situations, though, where some part of the tree, maybe an extended branch, could have a fungal issue, and that could be removed and the tree would be okay? Does that happen?

Chrissy: Absolutely. There's certain fungi that will come in into a wound and they'll colonize that wound. If the trees are healthy enough, or depending on the species of the tree and the species of the fungus that is infecting. Trees can usually compartmentalize off white rot if they're not very aggressive. It depends on the species of the tree and the species of the fungus whether or not it can actually be basically walled off from the tree. There's a fun fungus to identify. It's called Dryad's saddle or pheasant's back. That one is a notorious wound colonizer.

It's very, very weak as a pathogen, but it will go into that wound when a tree is pruned or has a limb fall in a storm. Usually, when it tries to progress, the trees are usually able to compartmentalize that off. That's a main one that I always think about when it's nothing too worrisome, but it's also something you see a lot in the environment.

Doug: When do I know that it's time to call my arborist if I see something in a tree?

Chrissy: If you are seeing dieback in the upper canopy of your tree, that's a huge one, especially with wood decay fungi. That means that the tree is super stressed out in the roots or in that vascular tissue. It's not able to get the nutrients it needs. That upper part of the canopy, when that part goes, it's really worrisome because it means that the tree is starting to give up. Throw the towel in, and it's done. The thing with wood decay fungi is that it's not always going to show those symptoms in the canopy. In that case, what tools you can use to know when to call the arborist is going to be looking for decay, obvious signs of decay at the base of the tree, or looking for those fungal fruiting bodies, but those won't always be there.

You're not always going to have that to fall back on. There could be decay going on without the fungal fruiting body being there at that time, you're there. In that case, just look for decay and anything weird going on. If animals are going in trees, they can use decayed part of trees for habitat. If you're seeing animals going into parts of your tree, maybe think about that. If you're seeing carpenter ants, they'll come into decay. They won't cause the decay, but there'll be proof decay is there. Those kinds of things can be really helpful to say, "Okay, I need to call the arborist because I know that there's some sort of decay." Whether or not it's detrimental, I don't want to find out the hard way.

Doug: If I do see that fruiting body, though, especially on the tree itself, I'm calling my arborist because I talk about this all the time, Chrissy. I'm in a declining oak forest. That's where I live. I looked up one day and I saw all this bright orange growth up in the tree, chicken of the woods mushroom. I call my arborist, and he's just like, "Yes, we'll come out and take a look at it," because sometimes, because that's not a big issue. When they started climbing up there, they got that hammer out. I could hear it from down below that it was hollow up there. In general, is that the thing we're supposed to do if we see a fruiting body on a tree, call the arborist?

Chrissy: Yes, absolutely. I know how to identify them. We know how to identify them. As a homeowner, the main stipulation I would use to call the arborist is just, is it connected to that woody tissue of the tree? If it is, and you're worried for other reasons, yes, call your arborist, and they should be able to identify the problem and go from there, for sure.

Doug: In most cases, we see that fruiting body. It's a bad thing, and the ship has sailed, but let's talk about prevention. What can we do as homeowners to prevent the problems that we've talked about here to make that tree happy? What are some of the things we can do?

Chrissy: My number one thing that I recommend to prevent wood decay fungi specifically from entering trees is mulch, because a lot of these fungi come into wounds. If we don't have mulch at the base of our trees, then people mow over the roots of their tree. That's the number one thing that I see homeowners doing that's so obvious to stop doing in order to prevent that infection from wood decay fungi. Specifically, it's also great for tree roots and retaining water and nutrients and all that. It's great in so many ways.

Mulching is my number one thing for that prevention, just because you're preventing so many wounds from happening in the future. That's number one. Then things like fertilization, watering your trees if there's drought, making sure there's proper drainage. All of the general PHC things you can do those, and that will prevent a lot of wood decay fungi from coming in.

Doug: If I'm mulching the wrong way, though, could I be promoting these fungal issues?

Chrissy: Oh, yes, you could. Absolutely. If you are mulching the wrong way, like volcano mulching, which I'm assuming you're referring to,-

Doug: Yes. [laughter]

Chrissy: -is actually making the perfect environment for fungi to come in and hang out because you're making that environment wet and inviting for them. Don't volcano mulch. What I mean by that is make sure you do not have a bunch of mulch put up around the tree's trunk. You want to have mulch around the tree's root zone and not too thick, only about 2 inches. The rules are 2 to 4 inches. I always just say 2 because people tend to go heavy on it. Then make sure that the mulch is not up, up the tree base.

You want to leave a little room, like an inch or 2 from that tree's trunk, so that does not happen, so you're not making that environment conducive for those fungi to grow and infect.

Doug: The other fungal issues that I was thinking about talking about, Chrissy, are leaf diseases. As we come into spring, we have that cool, wet weather. For somebody who grows a crabapple right outside the kitchen window, that thing always ends up with apple scab. Let's talk a little bit about those issues.

Chrissy: Yes. A lot of trees, most plants, every plant probably gets leaf diseases. The way that I like to think of the importance of the trees of how the pathogen can affect the tree is thinking about what part of the tree it's infecting and how it could hurt that. For a leaf disease, you are going to have issues with photosynthesis. That's going to be a disruption in photosynthesis. Now, that's obviously the most important thing for a plant to survive. If that's affected, it could be bad. However, leaf diseases are causing usually just little spots on the leaves.

Each little spot is a part that tree is not going to be able to make food from. However, there's so many leaves, and those spots are not the whole leaf. The trees can still make food, basically, is what I'm saying. It's actually not that detrimental to the trees in general. It can be more of an aesthetic thing with those leaf spots, which I know when we are in our urban environments and looking at our lawns and our trees, we want them to be perfect. I know aesthetics are important.

However, the good thing is a lot of those leaf spots or those leaf diseases are not going to be going after the health of the tree in general. They'll just cause some irritation to the tree, let's say.

Doug: Certainly, an issue ornamental-wise. In the case of something like a crabapple, where it drops its leaves after getting apples capped, can scare a homeowner into thinking that the tree is dying.

Chrissy: Yes, absolutely. That premature defoliation is the number one thing we hear about. People freak out. Rightfully so, like you said, it's in their yard for-- The trees are in their yards for beauty. When they're losing their leaves early on, especially when you're not expecting them to, and your neighbor's tree looks good and still has all its leaves, you're like, what the heck happened? It is something that is very aesthetically unpleasing and upsetting. Unfortunately, just something, especially with the crabapples, even if you treat those trees with-- If you spray those trees for that leaf disease, it's still going to have them, unfortunately.

A lot of these things, we go chasing and we can treat for. However, if there's enough of that pathogen there, the canopy is just going to lose it. It's an unfortunate thing we have with our ornamentals and leaf disease, especially those crabapples.

Doug: That's why I have to enjoy my crabapple right outside the window while I'm doing the dishes. I enjoy seeing those flowers. That's actually a tree. I tell the story all the time. It's actually a tree that got hammered by a pine tree that fell on it. The team from Davey knew how much I love the tree. They said, "It's going to look funny now." In a few years, and it worked out this way, 10 years later now, you couldn't even tell that it's been pruned. That's a good thing. Chrissy, tell me a little bit about your job, what you do. What does that mean when you're a technical advisor for the Davey Institute?

Chrissy: Yes. It's a very broad term. The cool thing about it is we can all go our own routes of our specialties. Basically, what I do is I do a lot of outreach and teaching our local offices and other offices throughout Davey. I teach mostly about wood decay fungi. That's my specialty, and schtick. I love all things pathogens with trees. I get to teach people about trees, basically, and the pathogens that affect them, and how we can look out for that, how we diagnose that, and then how to deal with it. It's a pretty great job.

Doug: I know we've talked about it before, but how did this become your thing?

Chrissy: How did this become my thing? Oh, my gosh. How much time do you have? [laughter] I've always been interested in trees. Growing up, my dad was always like, "That's this kind of tree." Always IDing things in nature. I always loved that. I continued with that. Then fate had it, and I went to Alaska for an internship. Oh, my gosh. If you ever want to see mushrooms, you got to go to Alaska. It's insane there. I think that's truly when I fell in love with fungi. I was already working with plants. I decided, what can I do to put plants and fungi together? It came up with plant pathology, and here I am.

Doug: Listeners don't know this, but when we talk in these interviews, we can see each other. There's somebody laying behind you that's doing a little bit of dreaming off and on. Who is that?

Chrissy: Yes, that's my dog, Finn. He definitely is running in his dream, I think. I love that you can see that. [laughs] I think he's in a race.

Doug: My dog, Lulu, is at my feet, keeping my toes warm.

Chrissy: Hi, Lulu.

Doug: All right, Chrissy. Thank you so much for all the great information. Thanks for being back on the show. It was great to talk to you. We'll talk to you again soon.

Chrissy: Sounds good. Thank you so much for having me. Have a good one.

Doug: Well, it was fun to watch Chrissy's dog dreaming in the background as we talk fungus. All right, you tree lovers. I want you to tune in every Thursday to this Talking Trees podcast from the Davey Tree Expert Company. I'm your host, Doug Oster. As always, I would love for you to do me a favor. Subscribe to the podcast so you'll never miss an episode. If you've got an idea for a show, maybe a comment, there's a couple of different ways to reach us. You can send an email to podcasts@davey.com. That's P-O-D-C-A-S-T-S@D-A-V-E-Y.com, or you can also click on the link at the end of our show notes to text us a fan mail message. Your ideas could be on a future podcast.

As always, we'd like to remind you on the Talking Trees podcast, trees are the answer.

[00:19:45] [END OF AUDIO]